Marijuana is going mainstream. Attitudes toward the drug are changing, rules governing its use are shifting and more and more states are voting to legalize it.

With widespread acceptance will come, theoretically, more widespread use. And that raises a whole lot of interesting questions for public health researchers. How will legal marijuana affect our children? Our jobs? Our relationships?

Or how about our sex lives?

That latter question inspired a research project by Joseph Palamar and his colleagues at New York University. “Since the landscape is changing, and marijuana continues to increase in popularity, research is needed to continue to examine if and how marijuana use may influence risk for unsafe sexual behaviour,” they write in the July issue of the journal Archives of Sexual Behavior.

To that end, Palamar and his colleagues recruited 24 heterosexual adults to take part in a series of in-depth interviews about prior sexual experiences that happened under the influence of either alcohol or marijuana. This isn’t a national sample by any means, and it’s not meant to be. Rather, the purpose was to obtain a rigorous qualitative assessment of the different effects of alcohol and marijuana on people’s sexual behaviours and to use this as a jumping-off point for future quantitative research.

Here are a few of the observations the researchers drew from the interviews.

With weed I know who I’m waking up with. With drinking, you don’t know. Once you start drinking, everybody looks good

1. Beer goggles are real.

Respondents “overwhelmingly reported that alcohol use was more likely to (negatively) affect the partners they chose,” the study found. Both men and women were fairly likely to say that alcohol had the effect of lowering their standards for who they slept with, in terms of character and appearance. With marijuana, this seemed to be much less of an issue.

“With weed I know who I’m waking up with. With drinking, you don’t know. Once you start drinking, everybody looks good,” a 34-year-old female said.

Marijuana use also was more associated with sex with people the respondents already knew — girlfriends and boyfriends, for instance. But alcohol “was commonly discussed in terms of having sex with strangers (or someone new),” the study found.

2. Drunk sex often leads to regret. Stoned sex typically doesn’t.

“The most commonly reported feeling after sex on alcohol was regret,” the study found. “Both males and females commonly reported that regret, shame, and embarrassment were associated with alcohol use, but this was rarely reported for marijuana.”

“I want to cook the person something to eat (after sex) when I’m high,” one male respondent said. “When I’m drunk, it’s like, ‘I’m out of here.’ Or get away from me.”

These negative emotions are probably at least partly due to drunk sex being associated more with strangers.

Another told of multiple instances where sex had to be interrupted because ‘I’ve had to stop and go hurl.’

3. Drunk sex can make you sick. Stoned sex can make you distracted.

“Nausea, dizziness, feeling sick (and vomiting), and blacking out were commonly reported to be associated with alcohol use,” the study found. One male said he accidentally fell asleep during sex while drunk. Another told of multiple instances where sex had to be interrupted because “I’ve had to stop and go hurl.”

There were fewer adverse effects reported with marijuana, and these tended to be more mental. One respondent said that marijuana use lessened his motivation to have sex. Another reported that being high distracted her from the experience.

“You’re so high (on marijuana)… you start thinking sex is weird. ‘What is sex?’” a female respondent reported.

4. The pleasure is usually better on marijuana.

The study found that “alcohol tended to numb sensations and marijuana tended to enhance sensations.”

“Alcohol tends to be a lot more numb,” a male respondent said. “Everything is sort of blunted and muted, whereas with marijuana it’s intensified.”

This “numbness” was associated with a longer duration of sex while drunk. But that wasn’t necessarily a good thing.

It “sometimes lasts too long,” one female respondent said. “Compared to when you’re high — it feels so great and it might be a little shorter.”

The study found that both men and women reported longer and more intense orgasms on marijuana, with one woman reporting hers were “magnified at least by five times.”

Also, marijuana led to “more tender, slow, and compassionate sexual acts, and to involve more sensation and sensuality than alcohol,” the report found.

One participant interestingly pointed out that marijuana use decreased his likelihood of engaging in risk behaviour because while high he was too paranoid to give in

5. Drunk sex is riskier overall.

“With regard to sexual risk behaviour, the majority of participants felt that alcohol was riskier, sexually, than marijuana,” Palamar and his colleagues found. People typically said they exercised poorer judgment when drunk than when stoned, and were more likely to blackout and forget whom they were with, what they were doing or whether they used protection.

Participants generally didn’t note this type of behaviour with marijuana and said that while under its effects, they felt more in control overall. “One participant interestingly pointed out that marijuana use decreased his likelihood of engaging in risk behaviour because while high he was too paranoid to give in,” the study found.

There are some useful take-homes here from a public health perspective. First, the findings confirm one thing that numerous other studies have shown: Alcohol use seems to be closely associated with high-risk sexual behaviour.

Aside from the link with unprotected sex and the corresponding risk of unexpected pregnancy or sexually transmitted diseases, studies have also drawn disturbing parallels between alcohol use and sexual assault. That link appeared even in the very small sample in Palamar’s study: One out of the 12 women interviewed reported an instance of sexual assault while under the effects of alcohol.

These negative consequences appear to be less pronounced with marijuana. Research found significantly lower incidences of domestic violence among couples who smoke marijuana, for instance.